1. Field of the Invention
The present invention relates to heat sinks, and more particularly to a heat sink having high heat dissipation efficiency.
2. Description of Related Art
With the development of the large scale integration semiconductor industry, the density of integration of an integrated circuit chip (the core component of many electronic systems) is becoming greater and greater, so the chip can run at unprecedented high speeds and generates large amounts of heat. The heat must be quickly and efficiently removed from the chip to keep the chip operable.
Generally, a heat sink abuts onto the chip to absorb and conduct the heat generated by the chip. Referring to FIGS. 5 and 6, a conventional heat sink 50 includes a rectangular base 52, and a plurality of parallel fins 54 extending up from the base 52 with channels 56 being formed between every two adjacent fins 54. In use, the heat sink 50 is attached onto a chip (not shown) via a bottom surface of the base 52 clinging to a top surface of the chip. A fan (not shown) is set, to assist in heat dissipation, at a certain distance from the heat sink 50. Airflow 58 from the fan enters into the channels 56 of the heat sink 50 through an air inlet 57 of the heat sink 10, and exits from an air outlet 59 of the heat sink 10. Thus, the heat generated by the chip is dissipated so that the chip can run within the normal work temperature range.
However, because of resistance of the fins 54 to the airflow 58, when the heated airflow 58 comes close to the air outlet 59 of the heat sink 50, the speed of the airflow 58 slows and the heated airflow 58 can not quickly exit from the heat sink 50, which impairs heat dissipation efficiency of the heat sink 50. In addition, partial airflow 582 of the heated airflow 58 flowing out of the air outlet 59 is guided by another system fan (not shown) to escape out of an electronic system, but main airflow 584 of the heated airflow 58 freely dissipates in the system, thereby impairing heat dissipation of the system.
What is desired, therefore, is a heat sink which has high heat dissipation efficiency and facilitates heat dissipation of an electronic system in which the heat sink is positioned.